Acting Defense Secretary Patrick Shanahan is being investigated for allegedly showing favoritism to Boeing, where he worked for more than 30 years before joining the Pentagon.

"The Department of Defense Office of Inspector General has decided to investigate complaints we recently received that Acting Secretary Patrick Shanahan allegedly took actions to promote his former employer, Boeing, and disparage its competitors, allegedly in violation of ethics rules," a DoD IG spokesperson said on Wednesday.

The new defense chief, a former Boeing employee, has reportedly been extremely critical Lockheed Martin's F-35 Lightning II Joint Strike Fighter in private meetings, raising questions about whether he is bias in overseeing the largest weapons program in history.

The aviation world is abuzz with rumors that the U.S. Air Force is evaluating the purchase of a brand-new F-15X model of the legendary 45-year-old F-15 Eagle twin-engine fighter. Marcus Weisgerber first reported this possibility for Defense One, then expanded upon in an article by Tyler Rogoway at The Drive.

At the beginning of August, the Air Force slapped Boeing with a hefty contract for two 747-8 commercial jets to replace the decaying VC-25A aircraft that currently serve as the Air Force One fleet during President Donald Trump’s frequent jaunts around the world. While the contract couldn't come a moment sooner for the aging Reagan-era aircraft rife with technical glitches, then-president-elect Trump had previously pushed to cancel the $4 billion modernization plan to save the federal government money. “Costs are out of control,” Trump tweeted in December 2016. “Cancel order!”